Datuk Seri Gan Seong Liam started his career as a building engineer in PWD, Negeri Sembilan and also worked in the Design and Research Department in PWD, Kuala Lumpur.

He has ventured into property development since 1985 and owns a Class A contracting company. The various positions held and the companies managed are:-

- 1982 to 1984 - General Manager in Property Development in Negeri Sembilan

-1984 to 1993 - Executive Director and substantial shareholder of both Abad Jaya Construction Sdn Bhd (Class A Contractor) and Indah Sdn Bhd, a property development company who developed Taman Megah in Petaling Jaya

-1994 to 2001 - Executive Director and substantial shareholder of Ganz Tecnologies Bhd, a rubber gloves manufacturing company listed on the 2nd Board of KLSE

- 2001 till current - Advisor to Fitters Diversified Bhd in the field of renewable energy in China, India, Sri Lanka and Vietnam

Since 2010, Datuk Seri Gan is actively involved in formulating the business strategies and commercial opportunities for Maxim Group. Under his leadership, the Group has successfully launched the two commercial property development projects with the combined gross development value (GDV) of RM950 million, under Meridian Maxim Sdn Bhd and Trillion Maxim Sdn Bhd.

He is also the Managing Director of Wawasan Metro Bina Sdn Bhd, a wholly owned subsidiary of Tadmax Resources Berhad.

Tadmax Resources Berhad

Datuk Seri Gan Seong Liam is the father to Mr Gan Kuok Chyuan, an Executive Director and a substantial shareholder of Tadmax Resources Berhad.

No

Direct Interest - 41,571,936 shares 

Indirect Interest - 2,000,000 shares held through his son, Mr Gan Kuok Chyuan
                          - 31,944,444 shares held through Global Showcase Sdn Bhd